Trajectories of psychosocial and functional change during late life reflect a combination of age-related, disability-related, and mortality-related processes. The proposed research examines heterogeneity of change across multiple domains of function (physical impairments, medical conditions, cognition, social integration, and well-being) along multiple time axes (age, distance-to/from-disability, distance-to-death) using data pooled together from four interdisciplinary studies of individuals aged 70 to 100+ years old, (total N = 1,067) who were measured on up to 5 occasions over 12 years. These intensive, multivariate, longitudinal, pre-death, histories will be wed with innovative application of contemporary methods for the analysis of change in order to articulate with further specificity the aging, disablement, and terminal decline processes hypothesized to occur during late-life. Objectives include (1) determining whether age-, disability-, or death-related processes are the primary contributors to late-life change across these five domains, (2) examining potential predictors and mechanisms underlying late-life changes in functionality, and (3) developing novel methodological tools to describe the prototypical, multivariate change trajectories individuals follow as they age, transition into disability, and die. The project makes use of the unique, multidisciplinary, longitudinal aspects of the pooled data and employs contemporary and innovative methods. Empirical results will shed further light on how and why individuals age, transition to disability, and die in heterogeneous fashion, help identify the particular pathways by which more and more individuals might maintain a high quality of life into advanced ages, and yield practical information helpful for the design and implementation of preventive interventions. PUBLIC HEALTH RELEVANCE: The end of life is often characterized by costly deteriorations in functionality and health - seemingly inevitable declines that are associated with severe costs, both to individuals'well-being and to society. Despite the social and clinical relevance of late-life disablement, relatively little is known about the processes underlying psychosocial and functional declines, or how these changes are interrelated across domains. As a first step in identifying the pathways by which more of the elderly can maintain health and wellness, the major goal of the proposed research project is to obtain a better understanding of the processes that contribute to late-life changes in psychological, social, and physical function - insights that will allow for better and more efficient planning for the care needs of "at-risk" individuals and, more generally, what resources may be most effective in bolstering the health and well-being of our aging, transitioning, and dying population.